Abstract: The method of triaxial testing on single specimen proposed by ISRM (International Society for Rock Mechanics) needs to be further studied as the servo controlling performance, the deformation measurement techniques and the monitoring approach for rock failure have improved. MTS815 testing system is one of the most excellent instruments in rock mechanics testing for its outstanding loading system, controlling system and measurement system. Based on this system, conventional triaxial tests and multiple level loading triaxial test are carried out on single specimen of Jinping coarse crystalline marble. It is revealed that the strength parameters of internal friction angle and cohesion by single specimen method are both smaller than those by conventional triaxial compression test, and the gap between the two parameters gets smaller with the confining pressure increases. It is concluded that the triaxial tests on single marble specimen with multiple level loading are suitable, feasible and reliable for low and moderately hard brittle rock. The conclusions will be of great practical value for the determination of mechanical parameters under special conditions and for the promotion of this method.

Key words: MTS815  ,  triaxial test on single specimen  ,   conventional triaxial test  ,  stress level ,   strength parameters